Ornamental iron scroll bender



Feb. 4, 1958 M. J. AHERN 8223323 ORNAMENTAL IRON SCROLL BENDER Filed Nov. 25, 1955 3 sheets-sheet 1 IN VEN TOR. Ml HEL J. AHERN.

A T TORNE Y I UL M. J. AHERN ORNAMENTAL IRON SCROLL BENDER Filed Nov'. 25, 1955 34 Sheets-Sheet 2 INVENTOR. IW EL J. AHERN.

Y Du ATTORNEY.

Feb. 4, 1958 M.' J. AHI-:RN

ORNAMENTAL IRON SCROLL BENDER 5 sheets-sheet 5 Filed N OV. 25, 1955 INVEN TOR. J. AHERN.

AEL

A TTORNE Y.

nited States Patient O ORNAMENTAL IRUN SCROLL BENDER Michael J. Ahern, Inglewood, Calif.

Application November 25, 1955, Serial No. 548,843

8 Claims. (Cl. 153-40) This invention relates to means for bending metal bars and is specifically directed to a power-actuated apparatus for forming bar stock into spiral scrolls for the fabrication of ornamental iron work and the like.

Since ornamental iron work is customarily fabricated entirely by hand by highly skilled artisans, the cost is correspondingly high. There is a pressing need, therefore, for power-actuated machineiy to reduce the amount of handwerk involved.

While many ornamental iron scrolls consist of a single flat spiral turn of 360 or less, nearly every ornamental iron assembly includes several scrolls having spiral turns extending up to two complete revolutions. The present invention provides a compact power-actuated apparatus that may form a spiral scroll of two complete spiral turns in a single continuous bending operation. This bending operation may be carried out with high rapidity and requires no special skill whatsoever on the part of the operator.

The difficulty in attempting to form a at spiral scroll of two turns is that when the first turn is being formed, there is interference by the forming surfaces that are required for the subsequent second turn. The invention meets this problem by using two separate rotary forming dies comprising an inner rotary die for the initial turn and an outer rotary die for the second turn, these two dies being adapted for axial movement relative to each other.

At the start of a forming operation, the outer die is in a position offset from the plane of rotation of the inner die to avoid interfering with the bar stock during the initial forming operation by the inner die. If the scroll to be formed has only one spiral turn or less, the outer die remains in its offset position out of contact with the bar stock. If the scroll to be formed is a spiral extending over more than 360, however, the outer die moves axially into the plane of rotation of the inner die to carry out the latter part of the forming operation and does so in a time manner to permit the scroll to be formed in one continuous operation.

The apparatus of the preferred practice of the invention is further automatic in providing means that may be preset to stop the rotation of the two forming dies at any predetermined point throughout -a range of two complete revolutions. For this purpose the preferred practice of the invention includes a clutch for driving the two rotary dies in combination with a rotary stop gauge that may be adjusted to disengage the clutch at selected points in the range of two revolutions.

A feature of the preferred practice of the invention is the provision of a rotary stop gauge that is operatively connected with the two dies 'for rotation simultaneously therewith and that is provided with a clockspring or the equivalent. The clockspring serves to return the rotary stop gauge to its starting position automatically after each forming operation and since the two dies are operice are also returned automatically to their starting positions.

In the procedure of forming bar stock by rotary die means, it is necessary to hold Ithe bar stock against rotation with the die means thereby to cause the bar stock to wrap around the spiral forming surfaces of the die means. In this regard, a feature of the preferred prac-- tice of the invention is the provision of a special holding` roller to block any tendency of the bar stock to swing laterally out of its normal feed position. At the start, the holding roller is positioned relatively close to the inner rotary die to cause proper wrapping action of the bar stock and then automatically shifts outward for subsequent cooperation with the forming surfaces of the outer rotary die. As will be explained, the holding roller is not power-actuated and is not shifted by power but, nevertheless, is so mounted on a fixed guide means that it automatically makes the required outward shift in proper timing in reaction to the forming operation itself.

A further feature of the invention is that the two rotary dies are replaceably mounted in the apparatus. This provision makes it possible to use a series of interchangeable dies.

The various features and advantages of the invention may be understood from the following detailed description taken with the accompanying drawings.

In the drawings, which are to be regarded as merely illustrative:

Figure l is a plan view of the presently preferred ernbodiment of the invention;

Figure 2 is a View of the apparatus as seen along the line 2 2 of Figure l, with parts broken away to reveal concealed structure;

Figure 3 is a view similar to Figure 2 but taken at 90 therefrom;

Figure 4 is a horizontal sectional view taken as indicated by the line 4 4 of Figure 3, showing the rotary stop gauge as seen from above;

Figure 5 is a horizontal section view taken as indicated by the line 5 5 of Figure 2, showing the mechanism for raising the outer rotary die to the plane of rotation of the inner rotary die;

Figure 6 is a sectional view of the same mechanism taken along the line 6 6 of Figure 5;

Figure 7 is a perspective view of a replaceable inner rotary die;

Figure 8 is a plan view of an ornamental iron scroll that may be produced by the invention; and Figure 9 is a plan view of an ornamental iron assembly incorporating a number of scrolls such as shown in Figure 8.

General arrangement The fixed structure of the presently preferred embodiment of the invention includes a rectangular four-legged frame l0 carrying a top plate 12 and a shelf 14. The structure between the top plate l2 and the shelf 14 is surrounded by a housing 15, one side of which has a sliding door i6 (Figure 3). The top plate l2 has a circular opening lil therein which registers with what may be termed a yoke, generally designated 20, which is mounted on the underside of the top plate l2. As best shown in Figures 5 and 6, the yoke 20 has two spaced upright arcuate walls 22 which are interconnected by a bottom wall 24.

The principal moving parts of the apparatus include: an inner rotary die 25 which is separately shown in Figure 7 and which is normally mounted on the upper end of a driven shaft 26, as shown in Figure 6; a clutch 28 in the form of an axially slidable collar for releasably connecting the driven shaft 26 to the upper end of a atively connected to the rotary stop gauge, the two dies continuously rotating driveA shaft 30; an angular lever 32 a3' for 'controllingthe cl'u't'chi28; an adjustable rotary stop "gagefgeterally'designated34' (Figures 3and`4)"that is operatively connected to the driven shaft 26 to make one rotation when the driven shaft makes two rotations, which stop gage"has"a` IiniitrstjpYarrn'LSS;an'adjustable stop arm 36 on the stop gauge 34 to operate the clutcl'r'lever '32 yfor"auto"rnaticallly'terniinatinga forming operation; a ."s'piral clocks'pi'ng l38` operatively connectedto 'the rotary Stop gauge `for the purpose "of 'returning both the rotary stopgaugeia'rid the driven 'shafti26 to 'their original starting"positions'after a forming operation is completed; an 'oiiter"rotary"die `40 'which -'is` slidingly mounted on the VEupper'end'of'the'drive shaft 26," asbest shown in Figure 6, 'for movement'frorn a r normal''retracted position below lthe"in'n'er rotary die`25'to' an effective position inthe plane 'of rotation of the 'inner die, this outer rotary die 'having an upright'spiral `rib"41to provide a 'spiral forming surlface 'and having a peripheral notch 42 (Figure l) for cooperation with a xed'lug 43; a c'ollar`44 riding on a coiled 'spring`45'i1'iside the yoke 2i) to lift the outer rotary "die to'itshpper positiong a forked control lever 46 adapted vfor 'releasable engagement with a shoulder 4S of an upright bar 50 to hold the collar 44 in its normal' lower position; and a' holding roller 52 (Figures l and 3) to' lteep the bar'stoclt' from rotating witlt'the rotary dies, this hold- Iingirollery beingca'rried' by a laterally extending arml 54 of a carriage 55 that is slidably mounted 'on aguide or rail `56.

' Operation ATo make a scroll having a spiral turn of approximately 360, such as the scroll 6i) at one end of the piece of rornamental iron shown in Figure 8, the adjustable stop arm 36 of the rotary stop gauge 34 is positionedat approximately 180 from the desired effective' position of the arm. Since the rotary stop gauge rotates at only half the rate of the forming dies, this 180 position represents one full turn of the "driven 'shaft'26 that rotates the two dies` The control lever 46 is then liftedinto engagement-with the shoulder 4S against the opposition of the spring 45 to retract the spring-pressed collar 44 to its normal lower position.

The operator then uses his right hand rto pick -up a metal bar B, usesthe bar to push the carriage 55 back toits normal starting'position shown in Figure l and then inserts the end of the metal bar into a radial slot -62-in the inner die 25, which radial slot is bestsho'wn in Figure 7. At this'position, the metal bar rests lagainst the holding roller 52 as shown in Figure l.

When the metal bar is properly positioned in this'manner, the operator uses his left hand to raise rthe clutch control lever 32 to its upper effective position to cause the clutch 28 to connect the driven shaft Zi'with the continuously rotating drive shaft 30. rThe inner die rotates counterclockwise as viewed in Figure l and "with the holding roller 52 preventing corresponding rotation of the metal bar B, the metal bar wraps itself around the spiral forming surface of the inner rotary die.

When the inner die 25 has rotated approximately 360, the adjustable stop arm 36 of the rotary stop gauge 34 swings against the clutch control lever 32 to cause disengagement of the clutch 28. Since the forming operation is carried out against the opposition of the clock spring 38, the disengagement of the clutch 2S to free the driven shaft 26 from the continuously rotating'driven shaft 30 results in the clock spring returning both the rotary stop gauge and the two forming dies to their normal starting positions.

To form a spiral scroll of more than 360 but'no more than two complete rotations, such as the scroli'64l at one 'end of the ornamental iron bar in Figure 8, thev adjust- `able'stoparnt 36 is registered with the'limit stop' arm 35 to permit one' complete rotation of the rotary stop gauge and two complete rotations -of theforming dies. The forked control lever 46 is engaged withthe shoulder 48 lin the usual lrnanr'rer. The operatoruses thernetal bar'to push the carriage 55 back to its normal starting position,

"andinsertstheendofthebar intothe forming dic slot 62 in the usual manner.

Holding the rnetal bar in position with his right hand, the operator lifts the clutch control lever 32 with his left hand to start the forming operation and then immediately uses his left hand to tap or push the forked lever 46 out of engagement withithe shoulder 48. The release of thevforked lever from the shoulder 4S permits the spring' 4S'to` urge the collar 44 upward against the outer forming die 40 but the outer forming die is in a downwardly retracted position because the fixed lug 43 blocks its upwardpath.

For approximately the first 360 of rotation of the two forming dies the metal bar wraps itself around the inner rotary die 25 with no possibility of interference by the outer die 40 and then, as the wrapping action approaches the end of the spiral forming surface of the inner die, the recess42 in the duter die rotates into register with "the fixedI lug" 43 to permit the outer'rotary die to be snapped'upwardby the'force'of the'spring 45. At ythis upper position,"the 'outer forming die 40 operates 'in/the same plane as the inner' rotary die. The lupward shift ofthe outer rotary die 40 is timed to permit the forming operation to continuewithout interruption, the metal bar `wrapping itself around the forming surfaces of 'the two dies in rapid succession.

During `this forming operation, the holding roller 52 effectively serves its purpose of preventing rotation ofthe metal barand of causing' the metal bar to'wrap'around the spiral forming'surfaces of the two rotary dies. As the radius (of itheforming action increases during the second rotation 'of the' two rotary dies, the roller'SZ 'shifts to 'the`left as'viewed in'Figure l to continue its cooperation with theV metal bar.

Whenthetwo revolutionsof the rotary dies are cornpleted, the stop arms of the rotary 'stop 'gauge move againstthe' clutch control flever Vto disenga'ge the clutch andthe 'clock spring 38 yreturns the rotary 'stop gauge and lthe t'wo'rotary dies to their starting positions.

It' is apparent that vthe two operations described above on 'the two endsof a` bar maybe performed in. rapid successionl to produce the double or reverse vscroll shown in Figure 8. `Any`n`umber of such scrolls can be formed in'sue'cession vwith perfect duplication in each instance. Figure 9 xshows how such scrolls may be assembled toge'ther in the usual manner in the lfabrication'of ornamental iron. lWith a series of such interchangeable inner rotary'dies available and a matching series of 4outer rotary dies, scrolls of various dimensions and curvatu'res may be readily formed, and by wrapping ilat stock around the rotary dies, various scrollsofintermediate ydirr'iensi'o'ns and curvatures can Ybe obtained.

De'tals of construction kvThemechanism"of theapparatus iser'ierg'ized by a 'suitablel'm'otor 64't`hrou'gh reduction 'gearing in a ge'ar case 65 and the drive shaft"30extends"'upward from this-'gear case. The upperle'ndjof the drivev shaft'30 has a `pair-of'diar'rietrical lugs66 which may be formed by a suitablecross vpin and the lower end of the driven shaft 26has'a'similar Apair of diametrical lugs 68.

'Theclutch 'collar`728 is slidingly telescoped over the ends -off t\v`oshafts 26 and 30 and has longitudinal slots '70 in constant engagement with the two lugs 68 and additionallyis "formed with a pair of diametrically opposite clutch teeth `72 for engagement with the lugs 66 of the drive shaft'30. It is apparent that when the clutch collar-isr held its upper position shown in Figure 2 with theiteeth 72'but of engagement with the lugs 66, thef'driven shaft"26"wil1lbe 'disengaged from the drive shaft 30. `On ythe otherhand, when the clutch collar is lowered'intoengagement with the lugs v66, it interconnects the twoshafts for v'rotation in unison.

"I'he clutch control lever 32 vfulcruttlsorta pivot'pin 74 carried bya pair of fixed ears 75 and is provided with a suitable knob or handle 76 on its outer end. The inner arm 78 of the clutch control lever is forked at its end to engage a circumferential groove 80 in the clutch collar 28.

It is contemplated that when the clutch lever 32 is raised to its effective position for lowering the clutch collar 28 into engagement with the lugs 66, the clutch lever will be frictionally retained in this upper position the clutch lever 32 at its upper position and having a second similar detent notch 85 to seat the clutch lever at its lower position. The clutch lever 32 is constantly pressed lightly against the detent bar 82 by means of a suitable coiled spring 86 that is best shown in Figure 3. One end of the coiled spring 86 is connected to the clutch lever and the other end is connected to a xed post 83 v that extends upward from the shelf 14.

The adjustable rotary stop gauge 34 is carried by a base casting 90 that is mounted on the shelf 14 by means of suitable bolts 92. This base casting is formed with an upwardly extending boss 94 in which is mounted an upright spindle 95. The stop gauge is in the form of a wheel journalled on the spindle 9S and is formed with peripheral sprocket teeth 96 by means of which it may be driven simultaneously with the driven shaft 2.6 but at half the rate of rotation. The sprocket teeth 96 are engaged by al sprocket chain 98 driven by a relatively small sprocket100 on the driven shaft 26.

The rotary stop gauge 34 has a downwardly extending hub 102 which isengaged by the previously mentioned clock spring 38. As best shown in Figure 4, the outer end of the clock spring is anchored by an upright stop post 104 that extends upward from the base casting 90. 4The clock spring 38 is confined by a suitable cage comprising radial arms 105 that are upwardly bent at their outer ends, the radial arms being mounted on the boss 94 of the base casting.

The rotary stop gauge 34' has the previously mentioned radial stop arm 35 integral therewith. The second adjustable stop arm 38 is journalled on the spindle 95 and is apertured to receive a retaining pin 106' which retaining pin is'looped to'form a convenient handle. The

v rotary stop gauge has a circumferential series o-f bores 108 in its upper face to receive the retaining pin 106. Thus it is a simple matter to use the retaining pin 106 to position the arm 36 at selected angular positions relative to the.' body of the rotary stop gauge.

Figure 4 shows the adjustable stop ar-rn 36 positioned i relative to the rotary stop gauge body to cause disengage- Y ment of the .clutch after approximately 360 of forming with the stop post V104 to determine the starting position ofthe rotary stop gauge as well as the starting positlons of the two rotary forming dies. In addition, the

4. stop arm 35 will make contact with the clutch 32 to stop the forming operation at the end of two complete rota- Vtions of the forming dies and thus serves as a safeguard in the event that the adjustable stop arm 36 is absent or is not effectively secured by the retaining pin 106.

As best shown in Figure 6, the driven shaft 26 extends upward through a suitable bearing sleeve 110 formed by the yoke 20. The upper end of the driven'shaft 26 above the yoke is formed with an enlargement 112 of square cross section and the stem 114 (Figure 7) of the inner rotary die 25 seats removably in an axial bore 115 in this enlargement. The inner rotary die 25 may be secured in position by a removable cross pin 116.

The outer rotary die 40 has an extensive hub 118 with a passage of square cross section therethrough (Figure 6) by means of which the outer rotary die is slidingly mounted on the shaft enlargement 112 for rotation therewith and for axial movement thereon. Normally the outer rotary die 40 is positioned by gravity against the bottom wall 24 of the yoke. A thin fixed sleeve 122 embedded in the bottom wall of the yoke surrounds the hub 118 and serves as a guide means for thepreviiously mentioned spring-pressed collar 44.

The previously mentioned forked control lever 46 may be made of a pair of bars held together by lbolts 124 as shown in Figure 5 and may be operatively connected to the spring-pressed collar 44 by a pair of angular links 125. The forked control lever 46 is fulcrumed by a pivot bolt 126 in a pair of ears 128 integral with the yoke 20. The outer end of the forked control lever is movable in a guide slot defined by the previously mentioned upright bar 50 and a second similar bar 130 (Figure 3) and the lower limit position of the lever in this slot is determined by an adjustable stop screw 132.

The stop `screw 132 threads into a fixed nut 134 and may be secured in adjusted position by a second lock nut 135. When the forked control lever 46 is disengaged from the shoulder 48, it drops against the stop screw 132 under the force of the coiled spring 45 so that the stop screw 132 determines the level to which the outer rotary die 40 is lifted by the coiled spring. The stop screw is adjusted of course, to place the upper position of the outer rotary die 40 on the same level as the inner rotary die 25.

My description in specific detail of the presently preferred embodiment will suggest various changes, substitutions, and other departures from my disclosure that properly lie within the spirit and scope of the appended claims.

I claim:

1. In an apparatus for bending a bar into the form of a spiral scroll, the combination of: an inner rotary die having a forming surface of increasing radius of curvature corresponding to an angle of rotation of not substantially more than 360, an outer rotary die rotatably mounted mounted on the same axis as the inner die, said outer die having a forming surface continuing the increase in radius of curvature, said two dies being relatively movable axially between an initial disposition in digerent planes of rotation and a second disposition in the same plane of rotation; actuating means including a clutch to rotate said' two dies in unison for a forming operation; a control for said clutch movable between a clutch-engaging position and a clutch-disengaging position; a rotary stop gauge operatively connected with said dies to rotate simultaneously therewith from a starting position and to engage said clutch control aftera predetermined amount of rotation of the two dies to cause the clutch control to shift from its engaging position to its disengaging position; and spring means to oppose rotation of said stop gauge out of said starting position by said actuating means and to return the stop gauge to said starting position when said clutch is disengaged thereby to automatically return both the inner and outer dies to their starting position after a forming operation.

2. An apparatus as set forth in claim 1 in which said rotary stop gauge has an element rotatably adjustable thereon to engage said clutch control whereby the predetermined amount of rotation may be varied.

3. In an apparatus for bending a bar into the form of a spiral scroll, the combination of: an inner rotary die having'a forming surface of increasing radius of curvaturecorresponding' to an angle 'of rotationof not s ub- Stantiallyrnore than 360, an outer rotary die rotatably mounted on the'sarne axis asitheinner die, said outer die having a forming surface c ontinuingthe increasein radius of curvature, said outer die being axially'rnovable 'between a normal position out of the plane of rotation of said inner form and an operating position in said plane; J"yielding means to urgesaid outer form axially from its normal position to its operating positiong'iixedmeans jcooperatiye with said outer die to'prevent'movement of theouter die out ofits normalpo'sitioninto its operative position until the louter dierotates by a predetermined ajmonnt; manually releasablemeans normallyrest'raining said outer die atitsnormal position `to make saidl yielding means ineiective when saidouter die has rotatedby said predeterminedA amount; actuating means including a clutch'to rotate s aid twodies in unison from a starting `position for a forming operation; acontrol for said clutch irnovable betweena clutch-engaging positionv and a -clutchdisepgagingposition; a rotary stop V'gauge'operatively connejcted with said dies to `rotate simultaneously therewith fr om'a starting position and to engage said clutch control after a predetermined amount of rotation of the two dies to cause the clutch control to shift from its engaging position to its disengaging position; and spring means to oppose rotation of said stop gauge by said actuating means out of saidstarting position and to return the stop gaugetosaid starting position and thereby automatically return both the inner and outer forms to their starting position after a form-ing operation.

4. I n an apparatus for bending a bar into the form of aspiral scroll, the combination of: an inner rotary die having a for rn ing surface of increasing radius of curvature corresponding to an angle of rotation of not substantiaily more than 360, an outer rotary die rotatably mounted on the same axis as the innerdie, said outer die having a forming surface continuing the increase in radius of curvature, said two dies being relatively movable axially between an initial disposition in different planes of rotation and aseond disposition in the same plane of rotation; means to rotate vsaid inner die through a first stage of approximately 360 and to rotate both of the dies in unison through a second stage of continued rotation with said two dies at their initial dispositon during Athe first stage; means to'relatvely shift said ltwo dies from their initial dispositionto'their second disposition at'the end of said first stage; a fixed guide means; a carriage movable along said guide means; a holding roller carried Vby said carriage for contact with the side of said bar to r -prevent rotation of the bar by said dies, said carriage being movable along said guide means from a starting position, said holding roller being within the maximum radius of said outer die at said starting position of the ca'rlg m5, I n anapparatus for bending a bar into the form of agspiral scroll, the combination of: an inner rotary die having a forming surface'of increasing radius of curva- 'turecorresponding to an angle of rotationof not sub- 'stan'tially more than 360, an outer rotary die rotatably mounted on 'the -same axisV as the inner die, said outer die'having a'forming surface continuing the increase in radius of curvature, said outer'die being movableaxially between' an initial position in a different plane of rotation from saidinner die and a second position in the same pla`ne of rotation; power means to rotate said inner die 4through a first stage of approximately 360 with both die-s `at'theirfinitialpositions during the first stage andato rotate both of the dies in unison through a second stage of continuing rotation; `means to shift said router die from'- itsinitialposition to'its second Vposition at the' end of' said`tirst stage; "a clutch 'to operatively connect said power means to said two dies for rotation thereofj'spring means to oppose rotationbf said two dies through said dies to terminate 4said s'ecnd'stage and vto permitifsiaid spring means'to rotate 'the two dies back'to their starting positions.

6. An apparatus'as set forth infclaim 5, in'whichsaid i meansto disengage said clutch is 'a'djus'tablewith 'respect {toi-the amount of rotation of the two dies to which it responds'forl adjustrnentofthe'degree of which'the two dies bend a bar.

7. In an apparatus for bending a bar into th'form 'of a spiral scroll, the combinationof: a 'support'jstructiire having a top plateto serve as a rest for a bar' during a forming operation, said top having an aperture'the'rein; an inner rotary d ie having a forming 'surface'of increasing radius of curvaturev corresponding' 'to an 'anglelof rotation of not substantially more lthan ,'360,""s aid inner rotarydie being positioned above said aperture and above thejp'l'ane of said top plate with its yaxisf'of rotation perpendicular to the top plate; an outer rotary die rotatably n'ted on the same axis as the inner'die,l said outer die'having a forming surface continuing the increasevinl'radiusl of curvature, said outer die being movablefaxially through said aperture from a lower positionbelowthe planel of'the surface of said top plate andan upper'position ,adjacent said inner die to serve as a continuationof the Iinner die; yielding means urging said outer die from its lower'position to its upper position; al first manually r'e'leasable means to hold said outer die at its lower position'inpposition to said yielding means and a second rrieans to y'old said outer die in its'lowervposition in opposition toy s'aid yielding means, said second means being releasable'in response to a predetermined amount of rotation 'of said inner rotary die to ca use movement of said'foug'ter'i'otary die to its upper positionto continue the bending of a bar after initial bending of the bar by said inner rotary 8. In an apparatus for bending a bar` into the fori-n of a spiral scroll, the combi1 '1 atir n' of l an inner' rotary die having a forming surface of increasing radius'of ycurvature corresponding to an angle of rotation of not'sbsftantially more than 360, an ou'ter rotary die rotatably mounted on the same axis asfthe inner die, wsaid outer die having a forming surface continuing theincrease*` in radius of curvature, said outer die being movable'axially between an initial position in a different plane of 'rota tion from said inner die and a second position in fthe same plane of rotation; powermeans to'rotate said inner die through a first stage of approximately 360 with'bth dies at their initial positions during the 4first s tagejand'to rotate both of the dies in unison through a second'stageV of continuing rotation; meansy to shift said out'erldieI ffrom its initial position to its second position Aatthe endjofsaid first stage; a clutch to operatively connect saidp'ower means to said two diesfor-rotation thereof;l, s pring means to oppose rotation of said twodiesgthroughjsaid ltwo stages; and means to disengage'said clutch; said diseng'ag ing means including arotary member operatively' connected with said vtwo dies lfor rotation simultaneously therewith and astop means carried 'said rotaryumember to disengage said clutch, said stop means" be"i ng'ad justable on said rotary ymember to vary the 'extent of rotation of the two dies by `said powerm'eans.

References Citedv in the le of rthisp'atent UNITED STATES PATENTS U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,n 2 ,822,023 February 4, 1958 Michael J Ahern It is hereby certified that err-or appears in the printed specification of the above numbered patent requiring Correction and that the said Letuers Patent should read as corrected below.

Column 6, line 50 strike out "mounted", seoond'oeourrenoe; line 55 y for "digerent" read different Signed and sealed Johis ls'b day of April 1958..

(SEAL) Attest:

KARL H., AXLINE ROBERT C. WATSON b'besbing Officer Conmssioner of Patents 

